Pope Leo XIV's Brother Louis Prevost Also Battling Cancer, Wife Tells CBS News

Louis Prevost, the older brother of Pope Leo XIV who lives in Florida, is battling multiple myeloma, his wife Deborah Prevost confirmed to CBS News on Tuesday. The disclosure comes amid the Vatican's earlier announcement that the pope himself has been diagnosed with lung cancer following surgery to remove a nodular lesion from his right lung. The two brothers spoke by phone last week before Louis began a new clinical trial, Deborah Prevost said, as the family navigates simultaneous cancer diagnoses for both men. Deborah Prevost described the family as 'going through a lot' but expressed hope that the pope's cancer was caught in its very early stages. Deborah Prevost told CBS News that her husband Louis was first diagnosed with multiple myeloma in 2017. After undergoing treatment in 2019 that included stem cell treatment and a clinical trial, he was able to maintain the disease at what she described as a 'very low level.' However, she said he 'fell out of remission' three months ago. Deborah Prevost did not disclose what stage the cancer is currently in but confirmed that Louis is now enrolled in a clinical trial at a local hospital where he is being treated. Multiple myeloma is a type of cancer that affects plasma cells, according to the Multiple Myeloma Research Foundation. The news about Louis Prevost's condition follows the Vatican's announcement earlier on Tuesday that Pope Leo XIV underwent surgery confirming a diagnosis of lung cancer. The 71-year-old pontiff was diagnosed with lung adenocarcinoma after surgeons removed a nodular lesion from his right lung. The Vatican did not disclose what stage the cancer was in, whether it may have spread, or what further procedures or treatment the pope may need to undergo. Deborah Prevost said she had not heard about any potential radiation or chemotherapy treatment for the pope and could not comment on the specifics of his condition. Deborah Prevost said her husband and the pope spoke by phone last week before Louis went in for his clinical trial. 'He called to let us know what would be happening,' Deborah said. 'We keep praying, keeping spirits up for both of them.' Pope Leo XIV, born Robert Prevost, is the first U.S.-born leader of the Catholic Church. He grew up alongside his two older siblings, Louis and John, in the Chicago area. In an interview with CBS News in May 2025, after then-Cardinal Robert Prevost was chosen as the new pope, Louis Prevost reflected on his brother's early calling to the priesthood. 'While I was out playing boy games, you know, whether it was baseball, cops and robbers, tag, flashlight, whatever kid games, Rob used to like to play priest,' Louis Prevost said. 'Since way back then, he's had that calling.' He added, 'He will always be Rob. If we do get over there and do get to meet him, I'm still going to treat him like my little brother. Give him a hug, say 'Rob, you idiot, what have you done?' Take his hat off and give him a nuggie.' Deborah Prevost told CBS News the family was 'going through a lot' in light of both diagnoses but remained hopeful. She expressed optimism that Pope Leo's cancer was in the very early stages, though the Vatican has not publicly confirmed the stage of his disease. The family's focus, she indicated, is on supporting both men through their respective treatments while maintaining their spirits. The parallel health struggles of the pope and his brother have drawn attention to the personal dimensions of the pontiff's papacy, which began when Robert Prevost was elected as the first American to lead the Catholic Church.